Residues and risk assessment of organochlorine pesticides in surface soil of Shenyang suburbs

Organochlorine Pesticides(OCPs) of 21 samples in the surface soils of Shenyang suburbs were determined by gas chromatography with electron capture detector( GC- ECD), and the residual characteristics, sources of OCPs and ecological risk were analyzed. The results showed that the detection rate of OCPs reached 95 percent and the total concentrations ranged from being lower than the detection limit to 111.67 ng· g-1with a mean value of 26.91 ng· g-1. Compared with the soils of other cities in China,the levels of HCHs and DDTs in Shenyang were lower, but HCB were higher, while OCPs were dominated by DDTs and HCHs. The source of OCPs was studied, and the result indicated that OCPs might come from the early residues in the environment or the use of lindane, and the source of HCB should also include industrial production. Correlations between OCPs and physicochemical properties of soil demonstrated that total organic carbon( TOC) and soluble salt content strongly influenced the residues of OCPs.Meanwhile, according to the environmental risk assessment, DDTs may still have potential ecological impact on the study area.